The highest speed limits are generally 75 mph (121 km/h) in western states and 70 mph (113 km/h) in eastern states. A few states, mainly in the
Northeast Megalopolis, have 65 mph (105 km/h) limits, and Hawaii only has 60 mph (97 km/h) maximum limits. A small portion of the
Texas and
Utah road networks have 80 mph speed limits. While parts of
Louisiana are located east of the
Mississippi River, 75 mph limits are only posted west of the Mississippi River. Therefore,
Maine is the only state completely east of the Mississippi River to have a maximum speed limit of 75 mph.